LC412 Fizz Buzz

# time O(N) space O(1)
class Solution:
    def fizzBuzz(self, n: int) -> List[str]:
        res = []
        for i in range(n):
            i = i +1
            if i %5 == 0 and  i %3 == 0:
                res.append('FizzBuzz')
            elif i % 3 == 0 :
                res.append('Fizz')
            elif i %5 == 0:
                res.append('Buzz')
            else:
                res.append(str(i))
        return res

class Solution:
    def fizzBuzz(self, n: int) -> List[str]:
        # main idea: string contacnation. check for divisability for certain number instead of checking every combination
        # time O(N) space O(1)
        res = []
        for num in range(1,n+1):
            by_3 = (num % 3 == 0)
            by_5 = (num % 5 == 0)
            
            s = ""
            if by_3:
                s += "Fizz"
            if by_5:
                s += "Buzz"
            if not s:
                s = str(num)
            res.append(s)
        return res 

class Solution:
    def fizzBuzz(self, n: int) -> List[str]:
        # main idea: string contacnation. check for divisability for certain number instead of checking every combination
        # time O(N) space O(1)
        res = []
        d = {3:"Fizz",5:"Buzz"}
        for num in range(1,n+1):
            s = ""
            for k in d:
                if num % k == 0:
                    s += d[k]
            if not s:
                s = str(num)
            res.append(s)
        return res